Journal of The New England Water Works Association - Spring 2015 - (Page 67)

on preliminary batch reactor studies, the research team hypothesized that a fixed-bed BAC reactor system could be developed to simultaneously remove arsenic and oxy-anionic contaminants such as nitrate, in the presence of sulfate and iron naturally occurring in groundwater. APPROACH A system consisting of two fixed-bed BAC bioreactors in series was designed and seeded with BAC obtained from lab- and pilot-scale nitrate and perchlorate removal systems. These systems were originally seeded with a mixed community of microbes indigenous to natural groundwater. Using a simulated groundwater containing nitrate, arsenic, sulfate, and iron, and feeding acetic acid as the sole electron donor, we operated this system for over 1,000 days. During operation, the empty bed contact time (EBCT), backwashing strategy, and influent iron and sulfate concentrations were varied. System performance was monitored by measuring concentrations of total arsenic, iron, acetate, chloride, sulfate, and nitrate. Additional studies of microbial community composition and activity were performed using molecular biology methods. Solids deposited in the reactors were characterized using X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD). RESULTS/CONCLUSIONS Simultaneous removal of nitrate and arsenic was achieved in the fixed-bed BAC bioreactor system. Complete denitrification occurred, removing 50 mg/L (as NO3-) to below the detection limit of 0.2 mg/L. Initially, arsenic was reduced from 300 μg/L to below 20 μg/L, although performance varied during subsequent experiments and effluent concentrations ranged from 10 μg/L (the U.S. EPA and World Health Organization standard) to 50 μg/L. Bacteria present in the reactor system were identified by sequencing their 16S ribosomal RNA genes to be closely related to known nitrate-, sulfate-, and iron- reducing bacteria. Analysis targeting specific functional genes coding for enzymes in sulfate- and arsenate-reduction pathways ([bi]sulfite reductase and arsenate reductase) indicated the presence of sulfate- and arsenate- reducing bacteria throughout the depth of the BAC bioreactors. Additionally, specific functional activities measured through messenger RNA abundance profiles were correlated with terminal electron accepting process (TEAP) zones as indicated by concentration profiles of sulfate and arsenic along the depth of the BAC bioreactors. Iron sulfides, mackinawite and greigite, were found to be the dominant crystal phases in the system, suggesting that arsenic removal through adsorption to these solids was an important removal mechanism. It was further determined that sulfur was the nearest neighboring atom to arsenic, indicating that arsenic sulfides were present in the system, and were partially responsible for arsenic removal. By varying the EBCT between 40 and 27 minutes, it was determined that nitrate and arsenic removals were achievable at these EBCTs. However, other factors, such as iron and sulfate concentrations may determine the EBCT needed for optimal arsenic removal. Experiments varying iron and sulfate concentrations found complete nitrate removal under all conditions. Arsenic removal varied depending on the amount of iron and location of its addition (1st reactor or 2nd reactor). Influent sulfate concentrations tested included 22 and 50 mg/L, demonstrating the flexibility of this system for treating source waters with variable sulfate concentrations. The first BAC bioreactor was backwashed every 48 hours, whereas the second BAC bioreactor was only backwashed every 3-4 months. Initially, nitrogen gas was used during backwashing. Considering the practical advantages of air-assisted backwashing, including simpler operation, improved safety, and lower cost, the impact of air-assisted backwashing on system performance was evaluated. It was determined that overall nitrate and arsenic removals with long term use of either gas were comparable, although a slight impact on arsenic removal in the first BAC bioreactor was observed. It was determined that the two-column system helped keep arsenic concentrations in the final effluent low, even immediately after an air-assisted backwashing event. This study demonstrated that a fixed-bed BAC bioreactor system can simultaneously remove arsenic and nitrate from a simulated groundwater utilizing an inoculum originating from a mixed community of microbes indigenous to groundwater. Microbial and chemical analyses indicated that the microorganisms utilized dissolved oxygen, nitrate, sulfate, and arsenate as the electron acceptors in a sequential manner in the presence of acetic acid as the electron donor. Biologically produced Journal NEWWA March 2015 67

Table of Contents for the Digital Edition of Journal of The New England Water Works Association - Spring 2015

Officers of the New England Water Works Association
NEWWA 2015 Meeting & Event Schedule
On the Cover
DAF Pilot Study for Algae and DBP Reduction
Impact of Epa Drinking Water Stage 2 Disinfectant and Disinfectant by-Product Rule
Thermal Expansion Causes False Fire Alarms
Preserving the Historical Beacon Hill Reservoir Granite Tablets
Water System Profile : Town of Kingston, Massachusetts
Proceedings: New England Water Works Association 2013-2014 Committee Reports
Obituary: Cheryl Lynn Maduskuie
In Memoriam: Richard G. Small
Reports From the Water Research Foundation
Guidelines for the Preparation of Papers for Publication in the Journal of the New England Water Works Association
Guidelines for the Peer Review Option of the Papers Appearing in the Journal of the New England Water Works Association
Entry Form: Newwa David M. Erickson Groundwater Award
Index to Advertisers

Journal of The New England Water Works Association - Spring 2015

Journal of The New England Water Works Association - Spring 2015 - (Page cover1)
Journal of The New England Water Works Association - Spring 2015 - (Page cover2)
Journal of The New England Water Works Association - Spring 2015 - (Page 1a)
Journal of The New England Water Works Association - Spring 2015 - (Page 2a)
Journal of The New England Water Works Association - Spring 2015 - Officers of the New England Water Works Association (Page 3a)
Journal of The New England Water Works Association - Spring 2015 - Officers of the New England Water Works Association (Page 4a)
Journal of The New England Water Works Association - Spring 2015 - Officers of the New England Water Works Association (Page 5a)
Journal of The New England Water Works Association - Spring 2015 - Officers of the New England Water Works Association (Page 6a)
Journal of The New England Water Works Association - Spring 2015 - NEWWA 2015 Meeting & Event Schedule (Page 7a)
Journal of The New England Water Works Association - Spring 2015 - NEWWA 2015 Meeting & Event Schedule (Page 8a)
Journal of The New England Water Works Association - Spring 2015 - On the Cover (Page 9a)
Journal of The New England Water Works Association - Spring 2015 - On the Cover (Page 10a)
Journal of The New England Water Works Association - Spring 2015 - On the Cover (Page 11a)
Journal of The New England Water Works Association - Spring 2015 - On the Cover (Page 12a)
Journal of The New England Water Works Association - Spring 2015 - On the Cover (Page 13a)
Journal of The New England Water Works Association - Spring 2015 - On the Cover (Page 14a)
Journal of The New England Water Works Association - Spring 2015 - On the Cover (Page 15a)
Journal of The New England Water Works Association - Spring 2015 - On the Cover (Page 16a)
Journal of The New England Water Works Association - Spring 2015 - Preserving the Historical Beacon Hill Reservoir Granite Tablets (Page 19)
Journal of The New England Water Works Association - Spring 2015 - Preserving the Historical Beacon Hill Reservoir Granite Tablets (Page 20)
Journal of The New England Water Works Association - Spring 2015 - Preserving the Historical Beacon Hill Reservoir Granite Tablets (Page 21)
Journal of The New England Water Works Association - Spring 2015 - Preserving the Historical Beacon Hill Reservoir Granite Tablets (Page 22)
Journal of The New England Water Works Association - Spring 2015 - DAF Pilot Study for Algae and DBP Reduction (Page 1)
Journal of The New England Water Works Association - Spring 2015 - DAF Pilot Study for Algae and DBP Reduction (Page 2)
Journal of The New England Water Works Association - Spring 2015 - DAF Pilot Study for Algae and DBP Reduction (Page 3)
Journal of The New England Water Works Association - Spring 2015 - DAF Pilot Study for Algae and DBP Reduction (Page 4)
Journal of The New England Water Works Association - Spring 2015 - DAF Pilot Study for Algae and DBP Reduction (Page 5)
Journal of The New England Water Works Association - Spring 2015 - DAF Pilot Study for Algae and DBP Reduction (Page 6)
Journal of The New England Water Works Association - Spring 2015 - DAF Pilot Study for Algae and DBP Reduction (Page 7)
Journal of The New England Water Works Association - Spring 2015 - DAF Pilot Study for Algae and DBP Reduction (Page 8)
Journal of The New England Water Works Association - Spring 2015 - DAF Pilot Study for Algae and DBP Reduction (Page 9)
Journal of The New England Water Works Association - Spring 2015 - DAF Pilot Study for Algae and DBP Reduction (Page 10)
Journal of The New England Water Works Association - Spring 2015 - DAF Pilot Study for Algae and DBP Reduction (Page 11)
Journal of The New England Water Works Association - Spring 2015 - Impact of Epa Drinking Water Stage 2 Disinfectant and Disinfectant by-Product Rule (Page 12)
Journal of The New England Water Works Association - Spring 2015 - Impact of Epa Drinking Water Stage 2 Disinfectant and Disinfectant by-Product Rule (Page 13)
Journal of The New England Water Works Association - Spring 2015 - Impact of Epa Drinking Water Stage 2 Disinfectant and Disinfectant by-Product Rule (Page 14)
Journal of The New England Water Works Association - Spring 2015 - Impact of Epa Drinking Water Stage 2 Disinfectant and Disinfectant by-Product Rule (Page 15)
Journal of The New England Water Works Association - Spring 2015 - Impact of Epa Drinking Water Stage 2 Disinfectant and Disinfectant by-Product Rule (Page 16)
Journal of The New England Water Works Association - Spring 2015 - Thermal Expansion Causes False Fire Alarms (Page 17)
Journal of The New England Water Works Association - Spring 2015 - Thermal Expansion Causes False Fire Alarms (Page 18)
Journal of The New England Water Works Association - Spring 2015 - Preserving the Historical Beacon Hill Reservoir Granite Tablets (Page 19)
Journal of The New England Water Works Association - Spring 2015 - Preserving the Historical Beacon Hill Reservoir Granite Tablets (Page 20)
Journal of The New England Water Works Association - Spring 2015 - Preserving the Historical Beacon Hill Reservoir Granite Tablets (Page 21)
Journal of The New England Water Works Association - Spring 2015 - Preserving the Historical Beacon Hill Reservoir Granite Tablets (Page 22)
Journal of The New England Water Works Association - Spring 2015 - Preserving the Historical Beacon Hill Reservoir Granite Tablets (Page 23)
Journal of The New England Water Works Association - Spring 2015 - Preserving the Historical Beacon Hill Reservoir Granite Tablets (Page 24)
Journal of The New England Water Works Association - Spring 2015 - Preserving the Historical Beacon Hill Reservoir Granite Tablets (Page 25)
Journal of The New England Water Works Association - Spring 2015 - Preserving the Historical Beacon Hill Reservoir Granite Tablets (Page 26)
Journal of The New England Water Works Association - Spring 2015 - Preserving the Historical Beacon Hill Reservoir Granite Tablets (Page 27)
Journal of The New England Water Works Association - Spring 2015 - Water System Profile : Town of Kingston, Massachusetts (Page 28)
Journal of The New England Water Works Association - Spring 2015 - Water System Profile : Town of Kingston, Massachusetts (Page 29)
Journal of The New England Water Works Association - Spring 2015 - Water System Profile : Town of Kingston, Massachusetts (Page 30)
Journal of The New England Water Works Association - Spring 2015 - Water System Profile : Town of Kingston, Massachusetts (Page 31)
Journal of The New England Water Works Association - Spring 2015 - Water System Profile : Town of Kingston, Massachusetts (Page 32)
Journal of The New England Water Works Association - Spring 2015 - Water System Profile : Town of Kingston, Massachusetts (Page 33)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 34)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 35)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 36)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 37)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 38)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 39)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 40)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 41)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 42)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 43)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 44)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 45)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 46)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 47)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 48)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 49)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 50)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 51)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 52)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 53)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 54)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 55)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 56)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 57)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 58)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 59)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 60)
Journal of The New England Water Works Association - Spring 2015 - Proceedings: New England Water Works Association 2013-2014 Committee Reports (Page 61)
Journal of The New England Water Works Association - Spring 2015 - Obituary: Cheryl Lynn Maduskuie (Page 62)
Journal of The New England Water Works Association - Spring 2015 - In Memoriam: Richard G. Small (Page 63)
Journal of The New England Water Works Association - Spring 2015 - Reports From the Water Research Foundation (Page 64)
Journal of The New England Water Works Association - Spring 2015 - Reports From the Water Research Foundation (Page 65)
Journal of The New England Water Works Association - Spring 2015 - Reports From the Water Research Foundation (Page 66)
Journal of The New England Water Works Association - Spring 2015 - Reports From the Water Research Foundation (Page 67)
Journal of The New England Water Works Association - Spring 2015 - Reports From the Water Research Foundation (Page 68)
Journal of The New England Water Works Association - Spring 2015 - Reports From the Water Research Foundation (Page 69)
Journal of The New England Water Works Association - Spring 2015 - Guidelines for the Preparation of Papers for Publication in the Journal of the New England Water Works Association (Page 70)
Journal of The New England Water Works Association - Spring 2015 - Guidelines for the Peer Review Option of the Papers Appearing in the Journal of the New England Water Works Association (Page 71)
Journal of The New England Water Works Association - Spring 2015 - Entry Form: Newwa David M. Erickson Groundwater Award (Page 72)
Journal of The New England Water Works Association - Spring 2015 - Index to Advertisers (Page 17a)
Journal of The New England Water Works Association - Spring 2015 - Index to Advertisers (Page 18a)
Journal of The New England Water Works Association - Spring 2015 - Index to Advertisers (Page 19a)
Journal of The New England Water Works Association - Spring 2015 - Index to Advertisers (Page 20a)
Journal of The New England Water Works Association - Spring 2015 - Index to Advertisers (Page 21a)
Journal of The New England Water Works Association - Spring 2015 - Index to Advertisers (Page 22a)
Journal of The New England Water Works Association - Spring 2015 - Index to Advertisers (Page 23a)
Journal of The New England Water Works Association - Spring 2015 - Index to Advertisers (Page 24a)
Journal of The New England Water Works Association - Spring 2015 - Index to Advertisers (Page cover3)
Journal of The New England Water Works Association - Spring 2015 - Index to Advertisers (Page cover4)
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